Adding a UIViewController to [ EGLView sharedEGLView ]

I am working with MoPub to manage Ads in my app.
To incorporate MoPub, I created a new NSObject subclass that has a UIViewController in it. I then add this UIViewController object into [ EAGLView sharedEGLView ] using the addSubview: method, like so:

[ [ EAGLView sharedEGLView ] addSubview: myAdViewController.view ];

I then add MoPub’s AdView ( which is a UIView subclass ) into my own UIViewController object.
It works fine when I test on iPad 3 ( the one with Retina, not sure about the models ) which has iOS 6.0 installed. But when I test it on an iPhone 4S iOS 5.1 and on iPad 2 iOS 5.1, it doesn’t work, or more specifically, the UIView shows up but only occupies 1/3 of the screen.
I tried using [ [ UIApplication sharedApplication ] keyWindow ] for a fix but it won’t let touch propagate to the cocos2d-x game when the view is dismissed.

From what I’ve observed, if I try to add a UIViewController to [ EAGLView sharedEGLView ] on a device that is less than iOS 6.0, I will get the display glitch that I get.
Is there a way to fix this? Any help will be greatly appreciated.

In the meantime, I’ll try testing on more devices and see if my theory is correct. Thanks in advance.